Litho Forum voters stick with 193, 193i tools

LOS ANGELES  A vote among participants at the Litho Forum here Thursday (Jan. 29) heavily favored the use of 193-nm lithography, in both its "dry" and "wet" forms, for use in manufacturing in 2007 and again in 2009.

International Sematech asked 120 corporations represented at the meeting to fill out surveys, and 90 companies handed in the ballots. The two main questions pertained to what form of lithography companies planned to use in 2007, and in 2009, for the 65-nm and 45-nm nodes.

About 30 companies said they thought 193-nm immersion lithography would be ready in 2006. Most said it would be 2007 before "193i" would be ready for manufacturing.

Many companies voted for 157-nm only as a backup. For example, at the 45-nm node, only a smattering of companies thought 157-nm immersion tools would be used for making the 45-nm gates. For contacts at the 45-nm node, the most stringent lithography requirement, 193-nm immersion got three times as many votes as 157-nm immersion, said Walt Trybula, a Sematech senior fellow who served as chairman of the forum.

During the two-day meeting, it became clear that the three scanner companies, as well as the resist suppliers, are putting nearly all of their resources behind 193-nm scanners, bringing in both immersion techniques as well as very high numerical aperture lenses.

Extreme ultraviolet (EUV) lithography starts to make an impact in 2010 and 2011, Trybula said.

George Gomba, senior manager of lithography technology development at IBM Corp., said "all three of the major scanner vendors definitely have 193 immersion as their up-front solution, with 157-nm lithography as the backup," Gomba said.

He noted that the number of 157-nm resist samples that are being brought to Sematech for evaluation is way down. Also, the supplier reports about calcium fluoride quality showed less improvement than needed. That raises the question of whether a backup will be there if unforseen problems arise for 193 immersion next year, when real testing of the 193i systems is fully underway.

"It is clear that the 157-nm infrastructure is substantially delayed," Gomba said. Development of EUV and the other next-generation lithography solutions also have been impacted by the industry downturn, he added.